Jersey barrier

42-inch (110 cm)-high variation of the Jersey barrier known as an Ontario Tall Wall, used to deflect vehicles from crossing into the opposing lanes of traffic.

A Jersey barrier or Jersey wall is a modular concrete or plastic barrier employed to separate lanes of traffic. It is designed to minimize vehicle damage in cases of incidental contact while still preventing the crossover case of a head-on collision. Jersey barriers are also used to reroute traffic and protect pedestrians during highway construction, as well as temporary and semi-permanent protections against landborne attack such as suicide vehicle bombs. A Jersey barrier is also known in the western United States as K-rail, a term borrowed from the California Department of Transportation specification for temporary concrete traffic barriers, or colloquially as a Jersey bump. Plastic water barriers of the same general shape are also now commonly referred to as jersey barriers.

Their widespread use in road construction has led to wide application as a generic, portable barrier during construction projects and temporary rerouting of traffic into stopgap carpool and rush hour reversing highway lanes.[4]

The design of the Jersey barrier was specifically intended to minimize damage in incidental accidents and reduce the likelihood of a car crossing into oncoming lanes in the event of a collision. In common shallow angle hits, sheet metal damage is minimized by allowing the vehicle tires to ride up on the lower sloped face. Head-ons are minimized by gradually lifting the vehicle and pivoting it away from oncoming vehicles and back into traffic heading in its original direction.

First tested in 1968 by the then Department of Highways in Ontario, Canada, the Ontario Tall Wall is a variant of the Jersey barrier.[5] Standing at 42 inches (107 cm), it is 10 inches (25 cm) taller than the standard Jersey barrier. In Ontario, the Ministry of Transportation is replacing guiderails (steel guardrail and steel box-beam) with these barriers on 400-series highways.

Designs with two rectangular notches at the bottom (through the short axis) allow for forklift-style lifting by front-end loaders. Barriers meant for short-term placement—especially in military and security barrier uses—might include steel rebar loops embedded in the top surface for rapid hook-and-cable system lifting.

Hollow polyethylene barriers have been developed for short-term applications where portability is important. These plastic barriers are normally filled with water after placement on-site to provide a moderate level of crash protection. They are not designed to deflect vehicles, so vehicles may penetrate the barriers.[6] These barriers can also be filled with soil, spill, or concrete to produce a heavier barrier with greater crash protection, at the cost of reduced portability.